This project is aimed at investigating mechanisms that might predispose to chronic pulmonary disease or that might assist in the diagnosis of such lung disease. Investigation of the usefulness of the Serum Angiotensin-Converting-Enzyme as a diagnostic aid for Sarcoidosis is a major effort. The role of the enzyme's elevation in this disease is being investigated, and the role of macrophages in synthesizing and releasing the enzyme is being studied. Other disease entities are being screened for possibly also being associated with elevated levels of serum A.C.E. The role of abnormal transformation of cultured lymphocytes in Cystic Fibrosis is being studied. The nature of a blood factor in CF that induces this abnormality will be explored, as will be the usefulness of this phenomenon for detecting the CF heterozygote. The role of an intermediate deficiency of alpha1-antitrypsin in predisposing to pulmonary emphysema will be further investigated.